Prostaglandins are a group of hormone-like substances which are known to play a critical role in virtually all body functions, including the control of the endocrine system, including insulin secretion. Elevated levels of insulin (i.e. hyperinsulinemia) are known to be strongly correlated with cardiovascular conditions such as hypertension, hyperlipidemia, Type II diabetes, and obesity [Reaven, G. M. Diabetes 37 1595-1607 (1988)]. The reduction of hyperinsulinemia results in a significant reduction of symptoms associated with any of these associated cardiovascular conditions.
Prostaglandins are directly effected by the diet. The role of diet in prostaglandin production is critical since the precursors of prostaglandins, known as essential fatty acids, cannot be made by humans and therefore must be supplied in the diet. Essential fatty acids are classified as either Omega 6 or Omega 3 depending on the positioning of their unsaturated double bonds within the fatty acid molecule. The typical essential fatty acids found in the diet are linoleic acid, (an Omega 6 essential fatty acid), and alpha linolenic acid (an Omega 3 essential fatty acid). However, the essential fatty acids normally found in the diet are not the actual precursors to prostaglandins. The body must further metabolize these commonly available essential fatty acids into more metabolically activated essential fatty acids. The rate limiting step in this further metabolism is controlled by the enzyme delta 6 desaturase. Once an essential fatty acid has progressed beyond this enzymatic rate determining step, it has a far greater impact on prostaglandin metabolism. We term essential fatty acids beyond this enzymatic step as "activated essential fatty acids".
U.S. Pat. No. 5,059,622 discloses that the ratio of activated Omega 6 essential fatty acids [such as gamma linolenic acid (GLA) or dihomo gamma linolenic acid (DGLA)] and activated Omega 3 essential fatty acids, such as eicosapentaenoic acid (EPA), will have a significant impact on the production of prostaglandins of the one series or production of prostaglandins of the two series. Prostaglandins of the one series (derived from DGLA) such as PGE.sub.1, have a beneficial impact on the cardiovascular system, whereas prostaglandins of the two series (derived from arachidonic acid [AA]) such as thromboxane A.sub.2 often have an adverse impact on the cardiovascular system. It is the dynamic balance of these two classes of prostaglandins, which is controlled by the diet, which will be a major factor in determining cardiovascular function.
The importance of maintaining an appropriate balance of prostaglandins of the one and two series is ultimately controlled by maintaining an optimal ratio of DGLA to AA. The ratio of DGLA to AA can be controlled through the dietary intake of the ratio of activated Omega 3 and Omega 6 essential fatty acids was disclosed in U.S. Pat. No. 5,059,622. It has been disclosed in U.S. Pat. No. 5,059,622 that the balance of activated Omega 3 essential fatty acids (in particular eicosapentaenoic acid or EPA) and activated Omega 6 essential fatty acids (either GLA or DGLA) has an impact on prostaglandin formation and the resulting reduction of hypertension. The appropriate ratio of EPA combined with gamma linolenic acid (GLA) or dihomo gamma linoleic acid (DGLA) would increase the amount of prostaglandins of the one series (such as PGE.sub.1) which are vasodilators while decreasing the relative amounts of prostaglandins of the two series (such as thromboxane A.sub.2) which are vasoconstrictors. The end result of this prostaglandin modulation would be reflected in the reduction of hypertension.